A technique for contactless transmission or reception of electric power to or from a device has recently attracted attention because it requires less effort on connection, or the like. Contactless charging has also found practical use for charging portable devices and electric automobiles.
Japanese Patent Application Publication No. 2010-172084 (Patent Document 1) discloses a coil unit for a contactless power feed device in which a coil is wound on a plurality of divided flat magnetic cores.                Patent Document 1: Japanese Patent Application Publication No. 2010-172084        Patent Document 2: International Patent Application No. 2011/016736        Patent Document 3: US Patent Application Publication No. 2010/259110        Patent Document 4: Japanese Patent Application Publication No. 2000-269059        